Pano blind pops and sticks before retracting
 

If the blind is designed like the rear window blind retracting is done by a spring that rolls the blind up much like the normal household window blinds do it.. The end of the blind moves with steel rods that expand and retract.

If it hesitates there is something that prevents the roll-up process to start freely. It could be something stuck on the blind material that does not want to allow the roll-up to start but then jumps over the "hump" and works.

I had a similar issue with the rear window blind that had some noise insulation foam fallen on the roller that then would not start immediately. The blind got very loose first before then finally starting to roll up.

Use silicone grease on the pano window track. Clean the track first, then apply the grease.

Use silicone grease on the pano window track. Clean the track first, then apply the grease.
This isn't exactly your model, but look at the video and you will get the idea.

The OP is talking about retracting the blind. The action for this is mechanical rods pulling the end of the blind back. His issue, I believe, is that when he retracts the blind the end starts moving but the roll-up function takes a delay. He can see this as the canvas gets loose before the spring loaded roll-up takes place.

Did I understand this correctly Peter?